<nav>
    <menu>
        <div id="acceso">
            <div id="log_in" class="boton_cabecera"><a name="barra_login" class="boton_mostrar" href="#">LOG IN</a></div>
            <div id="sign_up" class="boton_cabecera"><a href="sign_up.php">SIGN UP</a></div>
            <div id="become_add">
                <a href="become_member.php">Become a Member</a>
                    <span class="separador_barra">/</span>
                <a href="add_busines.php">Add your Business</a>
            </div>
        </div>
    </menu>
</nav>